This rapid, narrative review summarizes useful evidence from behavioral science for fighting the COVID-19 outbreak. We undertook an extensive, multi-disciplinary literature search covering five issues: handwashing, face touching, self-isolation, public-spirited behavior, and responses to crisis communication. The search identified more than 100 relevant papers. We find effective behavioral interventions to increase handwashing, but not to reduce face touching. Social supports and behavioral plans can reduce the negative psychological effects of isolation, potentially reducing the disincentive to isolate. Public-spirited behavior is more likely with frequent communication of what is “best for all”, strong group identity, and social disapproval of noncompliance. Effective crisis communication involves speed, honesty, credibility, empathy, and promoting useful individual actions. Risks are probably best communicated through numbers, with ranges to describe uncertainty – simply stating a maximum may bias public perception. The findings aim to be useful not only for government and public health authorities, but for organizations and communities.

Social distancing during the COVID-19 pandemic will save lives. We tested communication strategies to promote social distancing via an online experiment (N = 500) commissioned by Ireland's Department of Health. A control group saw a current informational poster. Two treatment groups saw similar posters with messages that highlighted: (i) the risk of transmission to identifiable persons vulnerable to COVID-19; (ii) the exponential nature of transmission. We then measured judgements of behaviours previously identified by focus groups as "marginal" (meaning that people were not sure whether they were advisable, such meeting others outdoors, or visiting parents). We recorded intention to undertake behaviours and stated acceptability of behaviours. Our hypotheses, that both treatments would increase participants' caution about marginal behaviours, were preregistered (i.e. lodged with an international organisation for open science before data collection). Results confirmed the hypotheses. The findings suggest that the thought of infecting vulnerable people or large numbers of people can motivate social distancing. This has implications for communications strategies. The study also demonstrates an effective way to identify outcome variables for rapid behavioural research on the COVID-19 response.

Social distancing during the COVID-19 pandemic will save lives. We tested communication strategies to promote social distancing via an online experiment (N = 500) commissioned by Ireland’s Department of Health. A control group saw a current informational poster. Two treatment groups saw similar posters with messages that highlighted: (i) the risk of transmission to identifiable persons vulnerable to COVID-19; (ii) the exponential nature of transmission. We then measured judgements of behaviours previously identified by focus groups as “marginal” (meaning that people were not sure whether they were advisable, such meeting others outdoors, or visiting parents). We recorded intention to undertake behaviours and stated acceptability of behaviours. Our hypotheses, that both treatments would increase participants’ caution about marginal behaviours, were preregistered (i.e. lodged with an international organisation for open science before data collection). Results confirmed the hypotheses. The findings suggest that the thought of infecting vulnerable people or large numbers of people can motivate social distancing. This has implications for communications strategies. The study also demonstrates an effective way to identify outcome variables for rapid behavioural research on the COVID-19 response.

Objective: Self-isolation is a vital element of efforts to contain COVID-19. We set out to test whether decision aids can support self-isolation. Design: We conducted a pre-registered online experiment with a nationally representative sample (n ¼ 500). Three stages tested: (i) whether decision trees help people to decide whether they need to self-isolate; (ii) whether an online planning tool increases people's confidence in their ability to self-isolate; and (iii) whether infographics help people to absorb advice on managing a household in which someone must self-isolate. Main Outcome Measures: (i) Accuracy of matching symptom patterns to a response scale for the need to self-isolate; (ii) selfreported confidence in coping with self-isolation; (iii) objective tests of recall and comprehension. Results: Decision trees improved decisions about when self-isolation was necessary, although participants systematically underestimated the need to self-isolate with less common COVID-19 symptoms (e.g. sore throat, fatigue). The online planning tool increased confidence about coping with self-isolation only among the adults aged under 40. Infographics improved recall and comprehension of how to manage self-isolation. Conclusion: Decision aids can be used to support self-isolation during COVID-19. The study also demonstrates how even an emergency public health response can benefit from rapid experimental pre-testing of interventions.

Self-isolation is a vital element of efforts to contain COVID-19. We report an online experiment with a nationally representative sample (N=500) that tested behaviourally informed decision aids to support self-isolation. The experiment had three stages that tested interventions designed to help individuals to: (i) decide whether they need to self-isolate; (ii) be confident in their ability to self-isolate should they need to; and (iii) manage a household in which an individual needs to self-isolate. Relative to prevailing public health advice, displaying decision trees improved participants’ decisions about when self-isolation was necessary, although they systematically underestimated the need to self-isolate in the presence of less common COVID-19 symptoms (e.g. sore throat, fatigue). Interaction with an online planning tool increased confidence about coping with self-isolation among adults aged under 40. Presenting advice in the form of infographics improved recall and comprehension of how to manage self-isolation. The study demonstrates how public health policy can benefit from behavioural pre-testing of interventions.